Car-lighting system.



S. KROHN.

CAR LIGHTING SYSTEM.

APPLIOATION FILED FEB. 28, 1907.

Patented June 15,1909.

Fig. l.

Fig. 2.

Witnesses:

1m TO OT tK Wm Va by S i M LN UNITED STATES PATENT SIGVALD KROHN, OF CHARLOTTENBURG, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CAR-LIGHTING SYSTEM.

Specification of Letters Patent.

Patented June 15, 1909.

Application filed February 28, 1907. Serial No. 859,886.

To all whom it may concern:

Be it known that I, SIGVALD KROHN, a subject of the King of Norway, residing at Charlottenburg, Germany, have invented certain newand useful Improvements in Car-Lighting Systems, of which the follbwing is a specification.

When translating devices of certain kinds are connected to a source of electric current, the potential of which is subject to variation,

it is often desirable to vary the resistance of the circuit as the potential changes in order to maintain constant the current passing through the translating devices. instead of changing the resistance of the circuit by the insertion and removal of resistances, the desired results may often be obtained by changing the arrangement of the various translating devices in the circuit. That is, if the translating devices or some of them have been connected in series, the total resistance which they offer to the circuit may be decreased by arranging them or some of them in parallel.

My invention relates to means for automatically varying the resistance of a circuit in this way as the potential of the source of current changes. Although it may be used in other connections, my invention is espe cially useful on electric railway lines which are at certain places supplied with current at.

1,000 volts and at other places with current at 500 volts.

More particularly stated, my invention re lates to the lighting service on the cars which are run on a railway line of this kind. it is obvious that if the incandescent lamps in the car are so connected as to run at maximum efliciency when the car is on the 500 volt stretch of track, that when the car runs into a 1,000 volt section there will be danger of burning out the lamps if some provision is not made for increasing the resistance in the circuit which supplies them in order to cut down the voltage and therefore the current which is supplied to them.

The particular forms of my invention which I have illustrated comprise means for automatically changing the arrangement of f with the accompanying drawings, in which the same reference characters refer to like i parts and in which Figure 1 is a diagrammatic view of apparatus and circuits used in carrying-out m invention; and Fig. 2 is a diagrammatic il ustration of a modified form 5 of my invention.

Referring to Fig. 1, T. and T are the terminals of the lam circuit which are intended to be connected irectly to the source of current, or, in other words, to the collecting device carried by the car and to the rails. The lamps are shown as arran ed in two grou. s 1 and 2, but it is obvious t at they mi t e arranged in any number of groups wit any of course, on the voltage for which t e lamps are adapted. For the purpose of controllin the arrangement of the groups of lamps, 1 preferably use electromagnetic switches, such as are diagrammatically shown at M and M. These may be of an well known form, of course, being designe for the service hereinafter described. As re resented the switches are in the position w ich they assume'when there is no voltage a plied to the circuit. Vl hen the terminals 'l and 'l of the lighting circuit are connected to the collecting devices and rails, which may be done by a switch in the usual manner, current will flow through the solenoid windings of the electromagnetic switches. A resistance R is arranged as usual in series with these solenoids in order to cut down the current which passes through them. The winding of the electromagnet switch M is such that this switch will be actuated only when a voltage of a proximately 1000 volts is applied to the lig ting circuit. The windin s or the switch M are,'however, such that this switch will be actuated when a much lower voltage is applied to the circuit, even a volta e considerably below the lowest voltage w ich is ever furnished by the line.

Assuming that the car is running on a 1000 volt section of line, the switch M will open,

thereby opening at 3 and 4 the circuit through the actuating coil of the switch M. The switch M is, therefore, not actuated and the groups of lamps are arranged in series, the circuit throu h them being as fol- Q lows: from T through the conductor a, i lam s 1, fixed contact 5, movable contact 6, 5 fine contact 7, lamps 2 and conductor 1) to f T If, however, the car now passes to a 500 volt section of line, the current passing rieswhile in the second form they are conthrough the switch M will be insuflicient to nested in parallel.

actuate this switch and it will close, thereby bridging thecontacts 3 and 4 and connecting the actuating coil of the switch M in circuit.

As before stated, this switch responds to a low volta e and will, therefore, at once operate, there y breaking the circuit between the contacts 5 and 7 and connecting the contacts 8 9 and 10 11 respectively. Thegrou s of lamps are now arranged in arallel an the circuits through them may e easily traced as follows: From the source T, through conductor a, to the point 0 where the current divides, part of it goin through lamps 1, fixed contact'8, movabe contact 6, fixed contact 9, conductors d and b to the other terminal T, the circuit through the other lamps being from c, throu h fixed contact 10, movable contact 12, fixer? 2 and conductor 1) to T It is seen, therefore, that when the car is on a 1000 volt stretch of line, the groups of lamps are connected in series and when the car is on a 500 volt 'section the groups are connected in parallel. In this way the proper voltage at the lamps is always automatically maintained.

Fig. 2 shows a somewhat sim ler arrangement, there being in this case ut one elec-- tromagnet switch. Thisswitch M is adapted in its 110-voltage position to connect the groups of lamps 1 and 2 in parallel. The Win mgs of the switch M are so designed that this switch will operate only'when the higher voltage is applied to the circuit; that is, it will operate at a voltage not lower than the lowest voltage which is sup lied when the car is on a 1000 volt stretch 0 line. As will be readily understood when the car is on a 500 volt section the current passing through the actuating coil of .the switch M will be insufiicient to operate the switch and the lamps will be connected in parallel, the circuits through them being as follows: From the source T, through the conductor a, to the point 0 where the current divides, part going through the lamps 1 to the fixed contact 13, through movable contact 14, fixed contact 15, and through conductors d and b to T; and from the point 0 to the fixed contact 16, movable contact 17, fixed contact 18, and lamps 2 and the conductor b to T hen, however, the car passes to a 1000 volt section, this switch M is actuated and the lamps are changed to a series arrangement. The circuit may-then be traced as follows: from the source T, through the conductor a, through lamps 1 to fixed contact 19, through mova le contact 17 to fixed contact 20, lamps 2 and conductor 1) to T The arrangement shown in Fig. 2 will, therefore, serve the same purpose as that shown in Fig.

1, the main diflerence being thatin the first contact 11, lamps it is obvious that my invention may be employed in connection with any number of groups of lamps or other translating devices, and the arrangement of such groups changed any number of times to the end that the source of current varying in potential may furnish a more or less constant current to each translating device or groups of translating devices. It is my intention to cover all such modifications and adaptations of my invention in the following claims.

Vvhat I claim as new and desire to secure by Letters Patent of'the United States, is

1. A lighting system for electric cars comprising a plurality of sets of lamps, a source of current varying in potential, and means for automatically changing the relative arrangement of the sets of lamps in the circuit as the potential at the source of current varies.

. 2. A lighting system for electric cars comprising a plurality of sets of lamps, a source of current varying in potential, and means for automatically varying the resistance in circuit as the potential varies by changing the relative arrangement of the sets of lamps.

3. A lighting system for electric cars comprising a plurality of sets of lamps, a source of current varying in potential, and means for automaticallychanging the arrangement of the sets of lamps from series to parallel or vice versa according as the potential of the source falls or rises.

4. A lighting system for electric cars comprising a plurality of sets of lamps, a sourceof current varying inpotential, and an electromagnetic switch for automatically changing the arrangement of the sets of lamps from series to parallel or vice versa according as the potential of the source falls or rises.

5. A lighting system for electric cars comprising a plurality of sets of lamps, a source of current varying in potential, and an electromagnetic switch having its actuating coil, connected to the source of current supply for automatically changing the arrangement of the sets of lamps from series to parallel or vice versa according as the potential of the source falls or rises 6. A lighting system for electric cars comprising a plurality of setsof lamps, a source of current varying in potential, an electromagnetic switch normally connecting the lamps in series but responsive to a low 0- tential for connecting the lamps in parallel and a second electromagnetic switch responsive only to a higher potential for interrupt ing the circuit through the actuating coil of the first mentioned switch.

7 In an electric railway system, a supply conductor having sections energized at different potentials, a car arranged for operation on either of said sections, a lighting system for said car comprising a plurality of sets of lamps, and means for automatically changing the relative arrangement of the sets of lamps in the circuit when the car passes from a section of line energized at one potential to a section energized at another.

8. In an electric railway system, a supply conductor having sections energized at different potentials, a car arranged for operation on either of said sections, a lighting system for said car comprising a plurality-of sets of lamps, and means for automatically changing the arrangement of the sets of lamps from series to parallel or vice versa, according as the potential of the supply conductor is greater or less.

9. In an electric railway system, a supply conductor having sections energized at different potentials, a car arranged for operation on either of said sections, a lighting system for said car comprising a plurality of sets of lamps, and an electromagnetic switch haviii'g its actuating coil connected to the source of current supply for automatically changing the arrangement of the sets of lamps from series toparallel or vice versa,. according as the potential of the supply conductor is greater or less.

10. In an electric railway system, a supply conductor having sections energizedat different potentials, a car arranged for operation on either of said sections, a li hting system for said car comprising a p urality of setsof lamps, and an electromagnet switch normally connecting the sets of lamps in series but responsive to a low potential for connecting the sets of lamps in parallel, and a second electromagnet switch responsive only to a higher potential for interrupting the circuit through the actuating coil of the first mentioned switch.

11. In an electric railway system, a supply conductor having sections energized at different potentials, a car arranged for operation on any of said sections, translating de. vices carried by said car and adapted tobe connected in circuit with said supply conductor, and means for automatically changing the relative arrangement of the translating devices in the circuit when the car passes from a section of line energized at one potential to a section energized at another. In witness whereof, I have hereunto set my hand this seventh day of February, 1907.

SIGVALD KROHN. Witnesses:

JULIUS RUMLAND, KARL KIEKEBEri. 

